TIMELINE-Cambodia's Khmer Rouge era

(Reuters) - Chief Khmer Rouge torturer Kaing Guek Eav, better known as "Duch," went on trial for crimes against humanity on Tuesday, 30 years after the fall of Pol Pot's regime, blamed for the deaths of 1.7 million people in Cambodia.

A handful of ageing and infirm leaders from the movement are due to be tried at a joint Cambodian-United Nations tribunal set up to prosecute "senior leaders" and those "most responsible" for one of the worst periods of the 20th century.

Below is an overview of the rise and fall of the Khmer Rouge:

1953 - King Norodom Sihanouk proclaims independence from France, but soon abdicates to go into politics.

March 1969 - Secret U.S. bombing of Vietnamese communist bases in Cambodia begins.

March 18, 1970 - U.S.-backed premier Lon Nol ousts Sihanouk as prime minister while the latter is on an overseas trip.

April 17, 1975 - Khmer Rouge seize Phnom Penh and immediately start emptying cities and towns in a bid to create a totally agrarian society. An estimated 1.7 million people die during their nearly four years in power.

Dec 25, 1978 - Vietnam starts invasion of Cambodia after a series of increasingly daring cross-border Khmer Rouge raids.

Jan 7, 1979 - Vietnamese troops occupy Phnom Penh, driving Pol Pot to the Thai border. The occupation is to last 10 years.